This invention generally relates to the field of paper making, and more specifically, to a high utility towel.
After hand washing, typically a paper-based hand towel is used to dry one""s hands, particularly in public restrooms. Often, a towel is used until its outer layers are wet. At that point, the wet towel is disposed and another towel may be dispensed to continue drying. Unfortunately, this practice fails to use the full absorptive capacity of the hand towel. Although the outer layers of the used towels are wet, they may still have absorptive capacity. Consequently, the failure to utilize this capacity wastes towels.
Accordingly, a hand towel that remains dry on its surface will reduce hand towel use by allowing the utilization of substantially the entire absorbency capacity of the towel, thereby reducing towel consumption rates and waste.
As used herein, the term xe2x80x9ccomprisesxe2x80x9d refers to a part or parts of a whole, but does not exclude other parts. The term xe2x80x9ccomprisesxe2x80x9d has the same meaning and is interchangeable with the terms xe2x80x9cincludesxe2x80x9d and xe2x80x9chas xe2x80x9d.
As used herein, the term xe2x80x9crepellant agentxe2x80x9d refers to an agent that resists absorption of a liquid, desirably an aqueous liquid. The repellant agent may be hydrophobic and includes materials such as sizing agents, silicon, waxes, and latexes.
As used herein, the term xe2x80x9clatexxe2x80x9d refers to a colloidal water dispersion of high polymers from sources related to natural rubber, such as Hevea tree sap, or synthetic high polymers resembling natural rubber. Synthetic latexes are made by emulsion polymerization techniques from styrene-butadiene copolymer, acrylate resins, polyvinyl acetate, and similar materials.
As used herein, the term xe2x80x9csiliconxe2x80x9d refers to a nonmetallic element or any compounds incorporating this element, such as the organosiloxane. Organosiloxane is any of a large group of siloxane polymers based on a structure consisting of alternate silicon and oxygen atoms with various organic radicals attached to the silicon. An exemplary silicon material is sold under the trade designation DOW 929 by Dow Chemical of Midland, Mich.
As used herein, the term xe2x80x9clayerxe2x80x9d refers to a single thickness, course, stratum, or fold that lays or lies over or under another. An exemplary several layered structure is depicted in FIG. 1, where a towel 10 includes five layers 14, 18, 22, 30 and 34.
As used herein, the term xe2x80x9cplyxe2x80x9d refers to a material produced from a headbox having one or more layers. An exemplary towel having a two-ply structure is depicted in FIG. 2, where a towel 50 includes two plies 54A and 54B.
As used herein, the term xe2x80x9cwaxxe2x80x9d refers to an aqueous emulsion of small particles held in suspension by an emulsifying agent. Exemplary waxes include paraffin waxes, microcrystalline wax, or other waxes. An exemplary wax compound that may be printed onto paper products is disclosed in U.S. Pat. Nos. 5,601,871, 5,614,293, and 5,665,426, which are hereby incorporated by reference.
As used herein, the term xe2x80x9csizing agentxe2x80x9d refers to any chemical inhibiting liquid penetration of cellulosic fiber structures. Suitable sizing agents are disclosed in a text entitled xe2x80x9cCellulosic and Paper Board Making,xe2x80x9d second edition, Volume III, edited by R. G. MacDonald, and J. N. Franklin, which is hereby incorporated by reference.
Particularly suitable sizing agents are acid or alkaline sizes such as acid rosin, alkenyl succinic anhydride, alkyl ketone dimers and alkenol ketene dimers of the formula: 
wherein R1 and R2 are based on C16-C18, aliphatic carbon chains, which can be the same or different. Exemplary commercially available sizing agents of this type are HERCON 79, HERCON 1332, and PRECIS 3000 from Hercules, Inc., Wilmington, Del.
As used herein, the term xe2x80x9ccellulosexe2x80x9d refers to a natural carbohydrate high polymer (polysaccharide) having the chemical formula (C5H10O5)n and consisting of anhydroglucose units joined by an oxygen linkage to form long molecular chains that are essentially linear. Natural sources of cellulose include deciduous and coniferous trees, cotton, flax, esparto grass, milkweed, straw, jute, hemp, and bagasse.
As used herein, the term xe2x80x9cpulpxe2x80x9d refers to processed cellulose.
As used herein, the term xe2x80x9cabsorbencyxe2x80x9d refers to the rate material completely soaks up a given quantity of a liquid over a specified time period. The absorbency rate of unsized papers may be measured using test procedure ASTM number D 824-94 and sized papers may be measured using test procedure ASTM number D 779.
As used herein, the term xe2x80x9cabsorbency gradientxe2x80x9d refers to the different absorbency capacity of various layers or plies in a towel product. Desirably, the inner layers or plies of the towel have greater absorbency than the outer layers.
As used herein, the term xe2x80x9cwickingxe2x80x9d refers to the rate at which a liquid is absorbed into a material as a result of capillary action. Results are typically reported as centimeter per minute. During testing, an about 25 millimeter by about 200 millimeter sample free of folds, wrinkles, and distortions is vertically and partially suspended in liquid, typically oil or water, at about 23 degrees Celsius and 50 percent relative humidity. Often, about 25 millimeter of the 200 millimeter sample length is immersed in the liquid. A weight may be attached to this end to prevent curling. The height of the leading edge of the liquid to the liquid surface is recorded at various time intervals, such as 0.25, 0.5, 0.75, and 1.0 minute, to determine the wicking rate.
As used herein, the term xe2x80x9cwicking gradientxe2x80x9d refers to the different wicking capacity of various layers or plies in a towel product. Desirably, the inner layers or plies of the towel have greater wicking than the outer layers.
As used herein, the term xe2x80x9csulfite pulpxe2x80x9d refers to pulp processed chemically with a mixture of sulfurous acid and bisulfite ion, which attack and solubilize the lignin in the pulp feedstock.
As used herein, the term xe2x80x9cbleached-chemical-thermo-mechanical pulpxe2x80x9d refers to processing cellulosic material with steam, pressure and sodium sulfite or hydrogen peroxide to soften wood lignin between and within cell walls. Furthermore, alkaline peroxide bleaching is added to further soften and brighten the cellulose fibers. The term bleached-chemical-thermo-mechanical pulp may be hereinafter abbreviated as xe2x80x9cBCTMPxe2x80x9d.
As used herein, the term xe2x80x9cbasis weightxe2x80x9d (hereinafter may be referred to as xe2x80x9cBWxe2x80x9d) is the weight per unit area of a sample and may be reported as gram-force per meter squared (hereinafter may be abbreviated as xe2x80x9cgsmxe2x80x9d). The basis weight may be measured using test procedure ASTM D 3776-96 or TAPPI Test Method T-220.
The problems and needs described above are addressed by the present invention, which provides a towel desirably including first and second layers having cellulosic fibers and a repellant agent. The first and second layers may substantially sandwich a third layer having cellulosic fibers with higher absorbency than the first and second layers. All three layers may form a single ply.
Furthermore, the towel may also include fourth and fifth layers positioned between, respectively, the first and third layers and the second and third layers. The fourth and fifth layers may have cellulosic fibers with higher wicking than the first and second layers.
In addition, the repellant agent may be wax, latex, a sizing agent, and/or silicon. Moreover, the repellant agent may be printed and/or sprayed onto at least one of the first or second layers. Furthermore, the repellant agent may be mixed with the fibers of at least one of the first or second layers in a headbox. What is more, the first or second layers may include sulfite pulp or BCTMP and the towel may have a basis weight from about 8 gsm to about 59 gsm. Furthermore, the third layer may have higher absorbency and wicking than the fourth and fifth layers.
Another embodiment of a towel may include a first ply further including a first layer having cellulosic fibers and a repellant agent, a second layer having cellulosic fibers with higher wicking than the first layer, and a third layer having cellulosic fibers with higher absorbency than the first and second layers. The second layer may be positioned proximate to the first layer and the third layer may be positioned proximate to the second layer. A second ply may be bonded to the first ply and be generally a mirror image thereof.
In addition, the repellant agent may be wax, latex, a sizing agent, and/or silicon. Moreover, the repellant agent may be printed and/or sprayed onto at least one of the first or second layers. Furthermore, the repellant agent may be mixed with the fibers of at least one of the first or second layers in a headbox. What is more, the first or second layers may include sulfite pulp or BCTMP and the towel may have a basis weight from about 8 gsm to about 59 gsm. Moreover, the third layer may have higher wicking than the second layer.